Intervals - minor/diminished (Edly's) ??

[Simon]

Hi - I'm working my way through Edly's Theory for Practical People; and actually quite enjoying it!

Hope someone will help me clarify stuff I don't quite 'get' on pp 29-30 (question below):

http://img187.imageshack.us/img187/2116/edlyintervalsp2930ev4.jpg

Statement 2.: lowered minor = diminished, I can't see that from the chart above, can I? E.g. m7 lowered (from 10 to 9 semitones) becomes º7 = dim7 -- is that right? .. the chart does not include any of these?

Or am I misreading something?
Thanks...

[Robert]

Hi Simon, I don't quite understand your question. You might have to email Edly and ask him.

[mark wein]

Hi - I'm working my way through Edly's Theory for Practical People; and actually quite enjoying it!

Hope someone will help me clarify stuff I don't quite 'get' on pp 29-30 (question below):

http://img187.imageshack.us/img187/2116/edlyintervalsp2930ev4.jpg

Statement 2.: lowered minor = diminished, I can't see that from the chart above, can I? E.g. m7 lowered (from 10 to 9 semitones) becomes º7 = dim7 -- is that right? .. the chart does not include any of these?

Or am I misreading something?
Thanks...

The chart doesn't show them.

They are not common usage for me, and for most music they are totally impractical.

A "Diminished 6th" is the same pitch as a Perfect 5th, which has an important structural role in harmony. If I was in the key of C and saw a Abb ("A double flat") I'd probably be confused for a minute but then realize that we are just dealing (in practical terms) with a perfect 5th.

An "Augmented 3rd" is a Perfect 4th. A "Diminished 4th" is a Major 3rd. Using these terms can couase quite a bit of confusion for those of us who are playing simple muisc (I know I am!). There must be a place in music for them because they are in every theory book I own but I have never run across a real practical use for these kinds of intervals....

[Robert]

Yeah, I'm with Mark. For diminished intervals and chords, just think of them as minor thirds stacked on top of each other. It makes them completely symmetrical - 1.5 whole-steps apart (or 3 frets). For example, C-Eb-Gb, which creates a C Dim chord.

[Simon]

Thanks guys!

[mark wein]

No problem!

[hubberjub]

For the most part it doesn't matter. It matters more if you are orchestrating something. It has to do with voice leading. Meaning, if you were to view each note being played in a chord as it's own separate melody, which direction is it going to move. Up to the next note or down to the next note. That's why we write using enharmonics in western music.

[tot_Ou_tard]

As far as I know, diminished is just another name for an interval which is flattened one semitone.

Most of the time such a flattened interval has another name, ie a flattened major third is called a minor third.

A flattened minor third (= major second) is called a diminished third if you want to emphasize that you are thinking of it as a modification of a third.

A flattened perfect fourth (= major third) is called a diminished 4th, if you want to emphasize that it is a modification of a 4th.

A similar consideration applies to intervals that are sharpened one semitone, here you use the term "augmented".

At least, that is how I understand it.